Display device

ABSTRACT

A display device includes a first substrate having a light shielding layer, and a second substrate having a first metal layer, a semiconductor layer formed over the first metal layer, and a second metal layer formed over the semiconductor layer. A sealing member fixes the first substrate and the second substrate, with a first scale mark formed over the first substrate, and a second scale mark formed over the second substrate and which forms a pair with the first scale mark. The light shielding layer has a first opening portion, and the first scale mark is arranged inside the first opening portion. The second scale mark is formed of a first part of the second metal layer, and a first part of the semiconductor layer and a first part of the first metal layer are overlapped with and extend off from the first part of the second metal.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. application Ser.No. 13/366,400, filed Feb. 6, 2012, the contents of which areincorporated herein by reference.

The present application claims priority from Japanese application JP2011-025574 filed on Feb. 9, 2011, the contents of which are herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a display device.

2. Description of the Related Art

A liquid crystal display panel has a structure in which liquid crystalis sandwiched between a pair of substrates. One of the pair ofsubstrates is a thin film transistor (TFT) substrate, and the otherthereof is a color filter substrate. On the TFT substrate, a largenumber of pixel electrodes are formed, whereas, a large number ofcolored layers are formed on the color filter substrate. It is necessaryto arrange the TFT substrate and the color filter substrate so that thepixel electrodes and the colored layers are aligned with each other.Conventionally, the liquid crystal display panel has been provided withscale marks for measuring a misalignment amount (dimension) between theTFT substrate and the color filter substrate (Japanese PatentApplication Laid-open No. Hei 10-104560 and Japanese Patent ApplicationLaid-open No. 2010-102134).

Because of the formation of the scale marks, light leakage of the liquidcrystal display panel has become a problem. As a countermeasure againstthe light leakage, there can be conceived a method of blocking off anopening through which light leaks by utilizing a metal film to be usedwhen forming the TFT substrate. However, in this case, the metal filmand the scale marks overlap one on top of another, which makes itdifficult to read the scale marks. Besides, the pair of substrates areadhered to each other by a sealing member, and the liquid crystal issealed in a space surrounded by the sealing member. Even when thesealing member overlaps the scale marks, it becomes difficult to readthe scale marks. The sealing member is more liable to overlap the scalemarks as the size of the region for the scale marks increases.

SUMMARY OF THE INVENTION

The present invention has an object to provide a display device capableof preventing reduction in visibility of scale marks.

(1) A display device according to an embodiment of the present inventionincludes: a first light transmissive substrate including: a displayregion in which an image is to be displayed in accordance with passingand blocking of light and intensity of the light; and a periphery regionsurrounding the display region; a light shielding portion formed in atleast the periphery region of the first light transmissive substrate,the light shielding portion having an opening portion in the peripheryregion; a first scale mark portion formed on the first lighttransmissive substrate so as to be arranged inside the opening portion;a second light transmissive substrate arranged so as to overlap thefirst light transmissive substrate; a thin film transistor, which isformed on the second light transmissive substrate, for controlling thepassing and blocking of the light and the intensity of the light; and asecond scale mark portion, which is formed on the second lighttransmissive substrate and forms a pair with the first scale markportion, in which: the second light transmissive substrate includes afirst metal layer, a semiconductor layer, and a second metal layer whichare laminated one on top of another; the thin film transistor is formedso as to include a part of the first metal layer, a part of thesemiconductor layer, and a part of the second metal layer; the secondscale mark portion is formed of another part of the second metal layer;under the second scale mark portion, another part of the semiconductorlayer is formed so as to extend off from the second scale mark portion;and below the second scale mark portion and the semiconductor layer,another part of the first metal layer is formed in a size capable ofshielding the opening portion. According to the present invention, thefirst metal layer shields the opening portion, and hence it is possibleto prevent light leakage from the opening portion. Further, the part ofthe semiconductor layer is positioned so as to extend off from thesecond scale mark portion, which is formed of the part of the secondmetal layer, from below. Through absorption of light by thesemiconductor layer, the second scale mark portion may be emphasized toenhance the visibility.

(2) In the display device described in the above-mentioned item (1), thesemiconductor layer may be made of amorphous silicon being a basematerial.

(3) A display device according to another embodiment of the presentinvention includes: a first light transmissive substrate including: adisplay region in which an image is to be displayed in accordance withpassing and blocking of light and intensity of the light; and aperiphery region surrounding the display region; a light shieldingportion formed in at least the periphery region of the first lighttransmissive substrate, the light shielding portion having an openingportion in the periphery region; a first scale mark portion formed onthe first light transmissive substrate so as to be arranged inside theopening portion; a second light transmissive substrate arranged so as tooverlap the first light transmissive substrate; a thin film transistor,which is formed on the second light transmissive substrate, forcontrolling the passing and blocking of the light and the intensity ofthe light; and a second scale mark portion, which is formed on thesecond light transmissive substrate and forms a pair with the firstscale mark portion, in which: the second light transmissive substrateincludes a first metal layer, a colored layer, and a second metal layerwhich are laminated one on top of another; the thin film transistor isformed so as to include a part of the first metal layer, a part of thecolored layer, and a part of the second metal layer; the second scalemark portion is formed of another part of the second metal layer; underthe second scale mark portion, another part of the colored layer isformed so as to extend off from the second scale mark portion; and belowthe second scale mark portion and the colored layer, another part of thefirst metal layer is formed in a size capable of shielding the openingportion. According to the present invention, the first metal layershields the opening portion, and hence it is possible to prevent lightleakage from the opening portion. Further, the part of the colored layeris positioned so as to extend off from the second scale mark portion,which is formed of the part of the second metal layer, from below.Through absorption of light by the colored layer, the second scale markportion may be emphasized to enhance the visibility.

(4) In the display device described in any one of the above-mentioneditems (1) to (3), one of the first scale mark portion and the secondscale mark portion may be set as a main scale mark, and another of thefirst scale mark portion and the second scale mark portion may be set asa vernier scale mark, to thereby enable measurement in a smallerdimension than the main scale mark.

(5) In the display device described in the above-mentioned item (4),each of the main scale mark and the vernier scale mark may include scalemark lines which are aligned in mutually opposite directions from areference scale mark line, to thereby enable measurement in a positivedirection and in a negative direction along the scale mark lines.

(6) In the display device described in the above-mentioned item (4), themain scale mark may include a first main scale mark and a second mainscale mark extending in parallel to each other, the vernier scale markmay include a first vernier scale mark and a second vernier scale markextending in parallel to each other, the first main scale mark and thefirst vernier scale mark may form a pair, the second main scale mark andthe second vernier scale mark may form a pair, the opening portion mayinclude a first opening portion and a second opening portion positionedrespectively on two sides sandwiching the display region, each of thefirst main scale mark and the first vernier scale mark may be arrangedso that, within the first opening portion, scale mark lines are alignedonly in a first direction from a reference scale mark line, and each ofthe second main scale mark and the second vernier scale mark may bearranged so that, within the second opening portion, scale mark linesare aligned only in a second direction, which is opposite to the firstdirection, from a reference scale mark line.

(7) The display device described in any one of the above-mentioned items(1) to (6) may further include: liquid crystal; a sealing member forsealing the liquid crystal between the first light transmissivesubstrate and the second light transmissive substrate; and a dam portionformed on the first light transmissive substrate. The sealing member maybe arranged in the periphery region of the first light transmissivesubstrate on the display region side with respect to the opening portionof the light shielding portion, and the dam portion may be arrangedbetween the sealing member and the opening portion so as to separate theopening portion from the sealing member.

(8) In the display device described in the above-mentioned item (7), thedam portion may be arranged in contact with the sealing member.

(9) A display device according to still another embodiment of thepresent invention includes: a first light transmissive substrateincluding: a display region in which an image is to be displayed inaccordance with passing and blocking of light and intensity of thelight; and a periphery region surrounding the display region; a lightshielding portion formed in at least the periphery region of the firstlight transmissive substrate, the light shielding portion having anopening portion in the periphery region; a first scale mark portionformed on the first light transmissive substrate so as to be arrangedinside the opening portion; a second light transmissive substratearranged so as to overlap the first light transmissive substrate; asecond scale mark portion, which is formed on the second lighttransmissive substrate and forms a pair with the first scale markportion; liquid crystal; a sealing member for sealing the liquid crystalbetween the first light transmissive substrate and the second lighttransmissive substrate; and a dam portion formed on the first lighttransmissive substrate, in which: the sealing member is arranged in theperiphery region of the first light transmissive substrate on thedisplay region side with respect to the opening portion of the lightshielding portion; and the dam portion is arranged between the sealingmember and the opening portion so as to separate the opening portionfrom the sealing member. According to the present invention, with thedam portion, it is possible to prevent the opening portion from beingcovered with the sealing member. In this manner, it is possible toprevent reduction in visibility of the first scale mark portion and thesecond scale mark portion.

(10) A display device according to yet another embodiment of the presentinvention includes: a first light transmissive substrate including: adisplay region in which an image is to be displayed in accordance withpassing and blocking of light and intensity of the light; and aperiphery region surrounding the display region; a light shieldingportion formed in at least the periphery region of the first lighttransmissive substrate, the light shielding portion including a firstopening portion and a second opening portion positioned respectively ontwo sides of the periphery region, which sandwich the display region; afirst scale mark portion formed on the first light transmissivesubstrate so as to be arranged inside the first opening portion; asecond scale mark portion formed on the first light transmissivesubstrate so as to be arranged inside the second opening portion; asecond light transmissive substrate arranged so as to overlap the firstlight transmissive substrate; a third scale mark portion, which isformed on the second light transmissive substrate and forms a pair withthe first scale mark portion; and a fourth scale mark portion, which isformed on the second light transmissive substrate and forms a pair withthe second scale mark portion, in which: one of the first scale markportion and the third scale mark portion is set as a first main scalemark, and another of the first scale mark portion and the third scalemark portion is set as a first vernier scale mark, to thereby enablemeasurement in a smaller dimension than the first main scale mark; oneof the second scale mark portion and the fourth scale mark portion isset as a second main scale mark, and another of the second scale markportion and the fourth scale mark portion is set as a second vernierscale mark, to thereby enable measurement in a smaller dimension thanthe second main scale mark; the first main scale mark and the secondmain scale mark extend in parallel to each other; the first vernierscale mark and the second vernier scale mark extend in parallel to eachother; each of the first main scale mark and the first vernier scalemark is arranged so that, within the first opening portion, scale marklines are aligned only in a first direction from a reference scale markline; and each of the second main scale mark and the second vernierscale mark is arranged so that, within the second opening portion, scalemark lines are aligned only in a second direction, which is opposite tothe first direction, from a reference scale mark line. According to thepresent invention, the scale mark extends only in one direction, andhence, within the opening portion, an area occupied by the scale mark isreduced. Therefore, the visibility is enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a plan view illustrating a display device according to anembodiment of the present invention;

FIG. 2 is an enlarged view of a corner portion of the display deviceillustrated in FIG. 1;

FIG. 3 is a sectional view taken along the line III-III of the displaydevice illustrated in FIG. 2;

FIG. 4 is a sectional view of the display device at a position differentfrom that of FIG. 3;

FIG. 5 is a view illustrating a first modified example of the displaydevice according to the embodiment;

FIG. 6 is a sectional view taken along the line VI-VI of the displaydevice illustrated in FIG. 5; and

FIG. 7 is a plan view illustrating a second modified example of thedisplay device according to the embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, an embodiment of the present invention is described withreference to the drawings.

FIG. 1 is a plan view illustrating a display device according to theembodiment of the present invention. FIG. 2 is an enlarged view of acorner portion of the display device illustrated in FIG. 1. FIG. 3 is asectional view taken along the line III-III of the display deviceillustrated in FIG. 2.

The display device according to this embodiment is a liquid crystaldisplay device, and hence includes liquid crystal 10 illustrated in FIG.3. By controlling the direction of molecules of the liquid crystal 10,passing and blocking of light and intensity of the light may becontrolled.

The display device includes a first light transmissive substrate 12 (forexample, glass substrate). The first light transmissive substrate 12includes, as illustrated in FIG. 1, a display region 14 in which animage is to be displayed. The image is formed of a plurality of (largenumber of) pixels (not shown), and is displayed in accordance with thepassing and blocking of the light and the intensity of the lightcontrolled in each pixel. That is, by controlling the liquid crystal 10,the image formed by the light is displayed. A periphery region 16 isprovided so as to surround the display region 14.

In at least the periphery region 16 of the first light transmissivesubstrate 12, a light shielding portion 18 is formed. The lightshielding portion 18 blocks light passage. In this manner, the peripheryregion 16 surrounding the display region 14 is darkened, to thereby makethe image more visible. The light shielding portion 18 includes, asillustrated in FIG. 2, a black matrix 20 arranged in the display region14. The light shielding portion 18 has opening portions 22 in theperiphery region 16. Light passes through the opening portions 22.Further, a first scale mark portion 24 is formed on the first lighttransmissive substrate 12 so as to be arranged inside each openingportion 22. The first scale mark portion 24 blocks light passage. Aplurality of scale mark lines 26 are aligned to form the first scalemark portion 24. As illustrated in FIG. 2, one of the plurality of scalemark lines 26 corresponds to a reference scale mark line 28. A linepositioned at the center of the plurality of scale mark lines 26 of thefirst scale mark portion 24 corresponds to the reference scale mark line28. The scale mark lines 26 are aligned in mutually opposite directionsfrom the reference scale mark line 28 so that measurement in a positivedirection and in a negative direction can be performed along the scalemark lines. The light shielding portion 18 and the first scale markportion 24 are made of the same material.

As illustrated in FIG. 3, the first light transmissive substrate 12includes a color filter layer 30. The color filter layer 30 is formed soas to cover the light shielding portion 18. The color filter layer 30also covers the opening portion 22, and further covers the first scalemark portion 24.

The display device includes a second light transmissive substrate 32(for example, glass substrate) which is arranged so as to overlap thefirst light transmissive substrate 12. The liquid crystal 10 issandwiched between the first light transmissive substrate 12 and thesecond light transmissive substrate 32. Note that, illustration ofalignment films is omitted.

On the second light transmissive substrate 32, a first metal layer 34, asemiconductor layer 36, and a second metal layer 38 are laminated in thestated order from the lower side (second light transmissive substrate 32side). “Laminate” means that layers are partially overlapped one on topof another. Therefore, there may be overlapping portions andnon-overlapping portions in the layers, and another layer may beinterposed between the layers. In the example illustrated in FIG. 3, aninsulating layer 40 is interposed between the first metal layer 34 andthe semiconductor layer 36. Further, a passivation film 42 is formed onthe second metal layer 38. The passivation film 42 covers thesemiconductor layer 36 and also the second metal layer 38, and furthercovers the insulating layer 40.

The first metal layer 34 and the second metal layer 38 are each made ofa metal such as aluminum, molybdenum, and chromium. The first metallayer 34 and the second metal layer 38 are often made of the samematerial, and in this case, a light reflectance ratio is the same.Therefore, the first metal layer 34 and the second metal layer 38, whichpartially overlap one on top of another so that ends thereof are offsetfrom each other, are visually indistinguishable when viewed from thesurface side.

The semiconductor layer 36 is made of amorphous silicon being a basematerial. The amorphous silicon has a red color, and hence thesemiconductor layer 36 may be used as the colored layer. Thesemiconductor layer 36 (colored layer) and the second metal layer 38have different light reflectance ratios or different colors, and hencethe second metal layer 38 and the semiconductor layer 36, whichpartially overlap one on top of another so that ends thereof are offsetfrom each other, are easily distinguishable when viewed from the surfaceside.

As illustrated in FIG. 3, on the second light transmissive substrate 32,a second scale mark portion 44 which forms a pair with the first scalemark portion 24 is formed. As illustrated in FIG. 2, a plurality ofscale mark lines 46 are aligned to form the second scale mark portion44. One of the plurality of scale mark lines 46 corresponds to areference scale mark line 48. A line positioned at the center of theplurality of scale mark lines 46 of the second scale mark portion 44corresponds to the reference scale mark line 48. The scale mark lines 46are aligned in mutually opposite directions from the reference scalemark line 48 so that measurement in a positive direction and in anegative direction can be performed along the scale mark lines.

In this embodiment, the first scale mark portion 24 is a main scalemark, and the second scale mark portion 44 is a vernier scale mark.Intervals between the scale mark lines 46 of the second scale markportion 44 is smaller than intervals between the scale mark lines 26 ofthe first scale mark portion 24. By reading the scale mark line 46 ofthe second scale mark portion 44, which coincides with the first scalemark portion 24, it is possible to measure a smaller dimension than thefirst scale mark portion 24 which is the main scale mark. Note that, asa modified example, the second scale mark portion 44 may be the mainscale mark, and the first scale mark portion 24 may be the vernier scalemark.

The second scale mark portion 44 is formed of a part of the second metallayer 38. Under the second scale mark portion 44, a part of thesemiconductor layer 36 (colored layer) is formed so as to extend offfrom the second scale mark portion 44. The semiconductor layer 36(colored layer) extends off from the second scale mark portion 44 so asto surround the entire outer periphery of the second scale mark portion44. Therefore, through absorption of light by the semiconductor layer 36(colored layer), the second scale mark portion 44 may be emphasized toenhance the visibility.

Below the second scale mark portion 44 and the semiconductor layer 36, apart of the first metal layer 34 is formed in a size capable ofshielding the opening portion 22. The first metal layer 34 shields theopening portion 22, and hence it is possible to prevent the lightleakage from the opening portion 22 of the light shielding portion 18.

FIG. 4 is a sectional view of the display device at a position differentfrom that of FIG. 3. On the second light transmissive substrate 32,there is formed a thin film transistor 50 for controlling passing andblocking of light and intensity of the light. The thin film transistor50 is formed so as to include a part of the first metal layer 34 (forexample, gate electrode 52), a part of the semiconductor layer 36 (forexample, channel region 54), and a part of the second metal layer 38(for example, drain electrode 56 and source electrode 58). Theinsulating layer 40 (gate insulating film) is interposed between thefirst metal layer 34 forming the gate electrode 52 and the semiconductorlayer 36 forming the channel region 54.

In this embodiment, the first metal layer 34 includes a portionshielding the opening portion 22 and a portion forming a part of thethin film transistor 50 (for example, the gate electrode 52). The secondmetal layer 38 includes a portion forming the second scale mark portion44 and a portion forming a part of the thin film transistor 50 (forexample, the drain electrode 56 and the source electrode 58). Thesemiconductor layer 36 (colored layer) includes a portion which extendsoff from the second scale mark portion 44 from below, and a portionforming a part of the thin film transistor 50 (for example, the channelregion 54). Therefore, the second scale mark portion 44 and the thinfilm transistor 50 can be formed of the same first metal layer 34,second metal layer 38, and semiconductor layer 36, and hence the numberof the manufacturing steps does not increase.

FIG. 5 is a view illustrating a first modified example of the displaydevice according to this embodiment. FIG. 6 is a sectional view takenalong the line VI-VI of the display device illustrated in FIG. 5. Inthis example, the liquid crystal 10 is sealed between the first lighttransmissive substrate 12 and the second light transmissive substrate 32by a sealing member 60.

The sealing member 60 is arranged in the periphery region 16 of thefirst light transmissive substrate 12 on the display region 14 side withrespect to the opening portion 22 of the light shielding portion 18. Thesealing member 60 is provided in close contact with mutually facingsurfaces of the first light transmissive substrate 12 and the secondlight transmissive substrate 32.

On the first light transmissive substrate 12, a dam portion 62 isformed. The dam portion 62 is arranged between the opening portion 22and the display region 14. For example, the dam portion 62 is positionedadjacent to the opening portion 22 on the display region 14 side.Further, the dam portion 62 is arranged between the sealing member 60and the opening portion 22 so as to separate the opening portion 22 fromthe sealing member 60.

Specifically, the sealing member 60 is formed by arranging and curing aresin precursor between the first light transmissive substrate 12 andthe second light transmissive substrate 32. In this process, the resinprecursor becomes a liquid or paste, and hence when the first lighttransmissive substrate 12 and the second light transmissive substrate 32are pressed so as to narrow a gap therebetween, the resin precursorattempts to expand in a direction toward the opening portion 22. In thiscontext, the dam portion 62 plays a role to stop the resin precursorright before the opening portion 22. With the dam portion 62, it ispossible to prevent the opening portion 22 from being covered with thesealing member 60. In this manner, it is possible to prevent reductionin visibility of the first scale mark portion 24 and the second scalemark portion 44.

The dam portion 62 is arranged in contact with the sealing member 60.Further, the dam portion 62 is arranged in contact (close contact) withthe first light transmissive substrate 12. In the example of FIG. 6, thedam portion 62 is not provided in contact with the second lighttransmissive substrate 32, and there is a gap therebetween. Even in thiscase, because the dam portion 62 is provided, flow resistance of theresin precursor can be enhanced, and hence it is possible to impede theprogress of the resin precursor. As a modified example, the dam portion62 may be arranged in contact (close contact) with the first lighttransmissive substrate 12 and the second light transmissive substrate32. For example, the dam portion 62 may be formed on the first lighttransmissive substrate 12 in advance, and when the first lighttransmissive substrate 12 is adhered to the second light transmissivesubstrate 32, the dam portion 62 may be pressed against the second lighttransmissive substrate 32.

FIG. 7 is a plan view illustrating a second modified example of thedisplay device according to this embodiment. FIG. 7 illustrates only apair of corner portions positioned on both sides of a diagonal line ofthe display device having a rectangular and planar shape.

In this example, the opening portion includes a first opening portion 64and a second opening portion 66 respectively positioned on two sidessandwiching the display region 14. The first opening portion 64 and thesecond opening portion 66 are symmetrical with respect to a point. Thepoint as a reference for the point symmetry may be a center portion(intersection point of diagonal lines) of the display region 14 when thedisplay region 14 has a rectangular shape, or may be a center portion(intersection point of diagonal lines) of the first light transmissivesubstrate 12 when the first light transmissive substrate 12 has arectangular shape.

Inside the first opening portion 64, a first main scale mark 68 and afirst vernier scale mark 70 are arranged to form a pair. The first mainscale mark 68 and the first vernier scale mark 70 are respectivelyarranged so that scale mark lines are aligned only in a first directionD₁ from reference scale mark lines 68 a and 70 a.

Inside the second opening portion 66, a second main scale mark 72 and asecond vernier scale mark 74 are arranged to form a pair. The secondmain scale mark 72 and the second vernier scale mark 74 are respectivelyarranged so that scale mark lines are aligned only in a second directionD₂, which is opposite to the first direction D₁, from reference scalemark lines 72 a and 74 a. Note that, the first main scale mark 68 andthe second main scale mark 72 extend in parallel to each other, and thefirst vernier scale mark 70 and the second vernier scale mark 74 extendin parallel to each other.

The first main scale mark 68 and the first vernier scale mark 70 enablemeasurement in the first direction D₁, and the second main scale mark 72and the second vernier scale mark 74 enable measurement in the seconddirection D₂. As described above, the scale marks extend only in onedirection, and hence, within the first opening portion 64 or the secondopening portion 66, an area occupied by the scale mark is reduced.Therefore, the sealing member 60 (see FIG. 6) does not cover over thescale mark, and the visibility of the scale mark is enhanced.

Further, in the example of FIG. 7, the opening portion further includesa third opening portion 76 and a fourth opening portion 78 respectivelypositioned on two sides sandwiching the display region 14. The thirdopening portion 76 and the fourth opening portion 78 are symmetricalwith respect to a point. The point as a reference for the point symmetrymay be a center portion (intersection point of diagonal lines) of thedisplay region 14 when the display region 14 has a rectangular shape, ormay be a center portion (intersection point of diagonal lines) of thefirst light transmissive substrate 12 when the first light transmissivesubstrate 12 has a rectangular shape.

Inside the third opening portion 76, a third main scale mark 80 and athird vernier scale mark 82 are arranged to form a pair. The third mainscale mark 80 and the third vernier scale mark 82 are respectivelyarranged so that scale mark lines are aligned only in a third directionD₃, which is orthogonal to the first direction D₁, from reference scalemark lines 80 a and 82 a.

Inside the fourth opening portion 78, a fourth main scale mark 84 and afourth vernier scale mark 86 are arranged to form a pair. The fourthmain scale mark 84 and the fourth vernier scale mark 86 are respectivelyarranged so that scale mark lines are aligned only in a fourth directionD₄, which is opposite to the third direction D₃, from reference scalemark lines 84 a and 86 a. Note that, the third main scale mark 80 andthe fourth main scale mark 84 extend in parallel to each other, and thethird vernier scale mark 82 and the fourth vernier scale mark 86 extendin parallel to each other.

The third main scale mark 80 and the third vernier scale mark 82 enablemeasurement in the third direction D₃, and the fourth main scale mark 84and the fourth vernier scale mark 86 enable measurement in the fourthdirection D₄.

Therefore, in addition to the measurement in the first direction D₁ andthe measurement in the second direction D₂ as described above, themeasurement in the third direction D₃ and the measurement in the fourthdirection D₄ can be performed. Therefore, similarly to theabove-mentioned embodiment, measurement in the positive direction and inthe negative direction can be performed.

The present invention is not limited to the above-mentioned embodiment,and various modifications may be made thereto. For example, thestructure described in the embodiment may be replaced by substantiallythe same structure, a structure which has the same action and effect, ora structure which can achieve the same object.

What is claimed is:
 1. A display device comprising: a first substratehaving a light shielding layer; a second substrate having a first metallayer, a semiconductor layer formed over the first metal layer, a secondmetal layer formed over the semiconductor layer; a sealing member fixingthe first substrate and the second substrate; a first scale mark formedover the first substrate; and a second scale mark which is formed overthe second substrate and forms a pair with the first scale mark; whereinthe light shielding layer has a first opening portion, and the firstscale mark is arranged inside the first opening portion; wherein thesecond scale mark is formed of a first part of the second metal layer,and a first part of the semiconductor layer and a first part of thefirst metal layer are overlapped with and extend off from the first partof the second metal; and wherein a width of the first part of the firstmetal layer is wider than a width of the first opening portion.
 2. Adisplay device according to claim 1, wherein the first scale mark andthe second scale mark are arranged outside the sealing member.
 3. Adisplay device according to claim 2, wherein the first substrate has adam portion, and the dam portion is arranged between the sealing memberand the first opening portion.
 4. A display device according to claim 1,wherein the first scale mark has a plurality of first scale mark linesextending in a first direction, and the second scale mark has aplurality of second scale mark lines extending in the first direction.5. A display device according to claim 4, wherein one of the first scalemark and the second scale mark is a main scale mark, and another of thefirst scale mark and the second scale mark is a vernier scale mark.
 6. Adisplay device according to claim 4, further comprising: a third scalemark formed over the first substrate, and a fourth scale mark which isformed over the second substrate and forms a pair with the third scalemark; wherein the third scale mark has a plurality of third scale marklines extending in the first direction, and the fourth scale mark has aplurality of fourth scale mark lines extending in the first direction.7. A display device according to claim 6, wherein the light shieldinglayer has a second opening portion, and the third scale mark is arrangedinside the second opening portion.
 8. A display device according toclaim 4, further comprising: a third scale mark formed over the firstsubstrate and a fourth scale mark which is formed over the secondsubstrate and forms a pair with the third scale mark; wherein the thirdscale mark has a plurality of third scale mark lines extending in asecond direction which is different from the first direction, and thefourth scale mark has a plurality of fourth scale mark lines extendingthe second direction.
 9. A display device according to claim 8, whereinthe light shielding layer has a second opening portion, and the thirdscale mark is arranged inside the second opening portion.
 10. A displaydevice according to claim 8, wherein one of the first scale mark and thesecond scale mark is a main scale mark, and another of the first scalemark and the second scale mark is a vernier scale mark; and wherein oneof the third scale mark and the fourth scale mark is a main scale mark,and another of the third scale mark and the fourth scale mark is avernier scale mark.
 11. A display device comprising: a first substratehaving a light shielding layer; a second substrate having a first metallayer, a colored layer formed over the first metal layer, a second metallayer formed over the colored layer; a sealing member fixing the firstsubstrate and the second substrate; a first scale mark formed over thefirst substrate; and a second scale mark which is formed over the secondsubstrate and forms a pair with the first scale mark; wherein the lightshielding layer has a first opening portion, and the first scale mark isarranged inside the first opening portion; wherein the second scale markis formed of a first part of the second metal layer, and a first part ofthe colored layer and a first part of the first metal layer areoverlapped with and extend off from the first part of the second metal;and wherein a width of the first part of the first metal layer is widerthan a width of the first opening portion.
 12. A display deviceaccording to claim 11, wherein the first scale mark and the second scalemark are arranged outside the sealing member.
 13. A display deviceaccording to claim 12, wherein the first substrate has a dam portion,and the dam portion is arranged between the sealing member and the firstopening portion.
 14. A display device according to claim 11, wherein thefirst scale mark has a plurality of first scale mark lines extending ina first direction, and the second scale mark has a plurality of secondscale mark lines extending in the first direction.
 15. A display deviceaccording to claim 14, wherein one of the first scale mark and thesecond scale mark is a main scale mark, and another of the first scalemark and the second scale mark is a vernier scale mark.
 16. A displaydevice according to claim 14, further comprising: a third scale markformed over the first substrate and a fourth scale mark which is formedover the second substrate and forms a pair with the third scale mark;wherein the third scale mark has a plurality of third scale mark linesextending in the first direction, and the fourth scale mark has aplurality of fourth scale mark lines extending in the first direction.17. A display device according to claim 16, wherein the light shieldinglayer has a second opening portion, and the third scale mark is arrangedinside the second opening portion.
 18. A display device according toclaim 14, further comprising: a third scale mark formed over the firstsubstrate and a fourth scale mark which is formed over the secondsubstrate and forms a pair with the third scale mark; wherein the thirdscale mark has a plurality of third scale mark lines extending in asecond direction which is different from the first direction, and thefourth scale mark has a plurality of fourth scale mark lines extendingthe second direction.
 19. A display device according to claim 18,wherein the light shielding layer has a second opening portion, and thethird scale mark is arranged inside the second opening portion.
 20. Adisplay device according to claim 18, wherein one of the first scalemark and the second scale mark is a main scale mark, and another of thefirst scale mark and the second scale mark is a vernier scale mark; andwherein one of the third scale mark and the fourth scale mark is a mainscale mark, and another of the third scale mark and the fourth scalemark is a vernier scale mark.